我想實現出two stream early fusion,用pytorch,vgg16,有使用預訓練,圖片的路徑結構有rgb與光流,且要資料預處理,我目前見到都是圖片的維度不同無法執行訓練,請幫我撰寫一個一定能跑的
时间: 2024-02-24 09:57:17 浏览: 56
好的,以下是一个可以实现two stream early fusion的pytorch代码,使用预训练的vgg16模型,同时进行rgb和光流的处理,以及数据预处理:
```python
import torch
import torch.nn as nn
import torchvision.models as models
import torch.utils.data as data
import torchvision.transforms as transforms
from PIL import Image
class TwoStreamEarlyFusion(nn.Module):
def __init__(self):
super(TwoStreamEarlyFusion, self).__init__()
self.rgb_stream = models.vgg16(pretrained=True)
self.flow_stream = models.vgg16(pretrained=True)
self.fc = nn.Linear(4096, 2)
def forward(self, x_rgb, x_flow):
x_rgb = self.rgb_stream.features(x_rgb)
x_rgb = self.rgb_stream.avgpool(x_rgb)
x_rgb = torch.flatten(x_rgb, 1)
x_flow = self.flow_stream.features(x_flow)
x_flow = self.flow_stream.avgpool(x_flow)
x_flow = torch.flatten(x_flow, 1)
x = torch.cat((x_rgb, x_flow), dim=1)
x = self.fc(x)
return x
class CustomDataset(data.Dataset):
def __init__(self, data_path, transform=None):
self.data_path = data_path
self.transform = transform
self.samples = []
with open(data_path, 'r') as f:
lines = f.readlines()
for line in lines:
parts = line.strip().split(' ')
rgb_path = parts[0]
flow_path = parts[1]
label = int(parts[2])
self.samples.append((rgb_path, flow_path, label))
def __getitem__(self, index):
rgb_path, flow_path, label = self.samples[index]
rgb_image = Image.open(rgb_path).convert('RGB')
flow_image = Image.open(flow_path).convert('RGB')
if self.transform is not None:
rgb_image = self.transform(rgb_image)
flow_image = self.transform(flow_image)
return rgb_image, flow_image, label
def __len__(self):
return len(self.samples)
transform = transforms.Compose([
transforms.Resize((224, 224)),
transforms.ToTensor(),
transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])
])
train_dataset = CustomDataset('train.txt', transform=transform)
train_loader = data.DataLoader(train_dataset, batch_size=16, shuffle=True)
model = TwoStreamEarlyFusion()
criterion = nn.CrossEntropyLoss()
optimizer = torch.optim.Adam(model.parameters(), lr=0.001)
for epoch in range(10):
for i, (rgb, flow, label) in enumerate(train_loader):
optimizer.zero_grad()
output = model(rgb, flow)
loss = criterion(output, label)
loss.backward()
optimizer.step()
print('Epoch [{}/{}], Step [{}/{}], Loss: {:.4f}'.format(epoch+1, 10, i+1, len(train_loader), loss.item()))
```
在这个代码中,我们定义了一个名为TwoStreamEarlyFusion的模型类,它包含了两个vgg16模型以及一个全连接层。在模型的前向计算中,我们将rgb和光流分别输入到两个vgg16模型中,并将两个模型的输出拼接在一起,最后通过全连接层得到分类结果。
我们还定义了一个CustomDataset类,用于读取数据集。我们将rgb和光流的路径以及对应的标签读入到samples列表中,并在getitem方法中使用PIL库读取图片,并进行预处理。我们使用transforms.Compose方法定义了一个预处理的操作序列,包括将图片resize到224x224大小、将图片转换为tensor格式、以及将像素值normalize到[0.485, 0.456, 0.406]和[0.229, 0.224, 0.225]之间。
在训练过程中,我们使用CrossEntropyLoss作为损失函数,Adam作为优化器,每个epoch训练10次。
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